Computer monitors are responsible for eye strain and vision problems. According to American Optometric Association, extensive use (more than 3-4 hours) of computer monitors, smartphones and tablets etc., is one of the main reasons for experiencing eye fatigue, blurred vision, dry eyes, and headaches. A person's optical system is designed to act as a natural filter protecting the eyes from undesirable or harmful rays. Although this human optical system provides significant protection against blue light rays coming from the sun, it is not biologically evolved to confront the blue light emanating from digital devices, or fluorescent-light tubes and LED lightning. Natural blue light is part of the visible light spectrum and it's considered to be beneficial, since it helps to regulate our body's biological clock, to trigger our body's growth mechanism and it plays an important role for people to feel euphoria. In other words blue light triggers our happiness feeling. As a part of visible light spectrum, natural blue light ought to not be totally blocked, as it would affect the quality of our vision by affecting color perception, it would disturb our growth mechanism and our body's internal clock. Nevertheless, LCD and LED computers monitors, TV's and smartphone devices emitting a different type of blue-violet light, which can have harmful impact on eyes and specifically on the retina.
Blue light- or high energy visible light- is emitted by the sun and can be beneficial to our growth as they help to regulate our bodies' internal clock by triggering the production of melatonin. Blue Light triggers the creation of Melatonin, a very important hormone that tells the body when it should sleep. However, over exposure to blue light, especially at the wrong times, can cause insomnia and sleep circle disruption. Additionally experts consider some types of blue light as the main factor for age-related macular degeneration, which affects the part of the retina responsible for our sharp central vision. Prolonged exposure to blue light may cause retinal damage and contribute to age-related macular degeneration, which can lead to loss of vision.
Ultraviolet (UV) radiation is around us, every day of our life, even on a cloudy day. UVB radiation links to the range of 280 nm to 320 nm, while UVA links to 320 to 380 nm in wavelength. We all know that UV radiation can affect our skin by increasing the risk of skin cancers, but excessive exposure to UV without wearing optical lenses and sunglasses can damage our eyes and could lead to early cataract, or temporary blindness caused by cornea sunburn. It's important to protect our eyes against UV even when we are indoors since sunlight can travel through windows.
It is estimated that on average, nine in ten adults spend more than two hours each day staring at a digital device, with more than six in 10 adults spending five or more hours on digital devices each day. All that time takes a toll on the eyes and lead to Digital Eye Strain.
Digital Eye Strain (D.E.S.) syndrome is the physical discomfort felt after two or more hours of work in front of digital monitors and it is associated with their artificial blue light emissions combined with the constant focus at close to mid-range distance. Electronic device monitors are emitting harmful artificial blue light, which in time harms the quality of tears layers and contributes to early occurrence of certain eye damages and syndromes (e.g. early cataracts and macular degeneration). Furthermore, spending significant amounts of time in front of a monitor causes blink rates to reduce, resulting to dry, itchy or burning eyes.
Bright lighting and too much glare can also strain your eyes, resulting to irregularities in contrast perception, which makes working on your monitor demanding. The worst contrast perception problems are generally from sources above or behind you, including fluorescent lighting and sunlight.
Examples of D.E.S. syndrome symptoms include headaches from repeated eye strains, blurred double vision or dizziness, dry eyes due to reduced blinking rate, eyelid aches during blinking due to blue light effect on tear layer quality, increased sensitivity to light, blurred vision due to screen glare, as well as general fatigue from staring at screens and straining to see small fonts and images.
Driving related eye strain is also common. When driving, one's eyes are constantly in motion, focusing and refocusing as objects approach, and contending with distractions, such as oncoming headlights or straining to see in very dim light. Under such conditions, the eyes become strained (Driving Eye Strain Syndrome), to the point where safety and visual effectiveness while driving can be severely impacted. Classical symptoms of driving eye strain include sore or itching eyes, watery or dry eyes, blurred vision, increased sensitivity to light, difficulty concentrating on the road, and difficulty keeping one's eyes open.
Digital eyestrain does not just affect adults. Children are also at risk for eyestrain due to the growing use of digital devices. Children today have more digital gear at their disposal than ever before—tablets, smart phones; videogames are just among a few. By some accounts, children and teenagers (ages 8-18) spend more than seven (7) hours a day consuming electronic media.
Before age ten (10), children's eyes are not fully developed. In an undeveloped eye, the crystalline lens and cornea are still largely transparent and overexposed to light. Too much exposure to blue light is particularly dangerous in kids for this reason, and parents have been advised to supervise and limit the amount of screen time exposure by kids.
Dark room type exposure to blue light—mainly from computers, smart phones and tablets in unlit (or poorly unlit) surroundings—is particularly harmful. While blue light normally triggers the creation of melatonin—an important and useful hormone that tells the body when it should sleep—over exposure to blue light, especially at the wrong times, can cause insomnia and sleep cycle disruption.
The use of blue-light filters on eyewear has proven useful in protecting eyes against harmful radiation. It is extremely desirable to be able to provide lenses with digital blue light filtering capability together with excellent contrast and sharpness performance to achieve a pleasant viewing experience.